Minki/linux
1
0
Fork 1
mirror of https://github.com/torvalds/linux.git synced 2024-09-21 23:43:02 +00:00
Code Issues Packages Projects Releases Wiki Activity

Merge branch 'for-5.15-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq

Browse Source 
Pull workqueue fixes from Tejun Heo:
 "One patch to add a missing __printf annotation and the other to enable
  deferred printing for debug dumps to avoid deadlocks when triggered
  from some contexts (e.g. console drivers)"

* 'for-5.15-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq:
  workqueue: fix state-dump console deadlock
  workqueue: annotate alloc_workqueue() as printf
This commit is contained in:
Linus Torvalds 2021-10-11 16:59:49 -07:00
commit 0a5d6c641b
2 changed files with 18 additions and 5 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

5
include/linux/workqueue.h
View File

@ -399,9 +399,8 @@ extern struct workqueue_struct *system_freezable_power_efficient_wq;
* RETURNS:
* Pointer to the allocated workqueue on success, %NULL on failure.
*/
struct workqueue_struct *alloc_workqueue(const char *fmt,
unsigned int flags,
int max_active, ...);
__printf(1, 4) struct workqueue_struct *
alloc_workqueue(const char *fmt, unsigned int flags, int max_active, ...);
/**
* alloc_ordered_workqueue - allocate an ordered workqueue

18
kernel/workqueue.c
View File

@ -4830,8 +4830,16 @@ void show_workqueue_state(void)
for_each_pwq(pwq, wq) {
raw_spin_lock_irqsave(&pwq->pool->lock, flags);
if (pwq->nr_active || !list_empty(&pwq->inactive_works))
if (pwq->nr_active || !list_empty(&pwq->inactive_works)) {
/*
* Defer printing to avoid deadlocks in console
* drivers that queue work while holding locks
* also taken in their write paths.
*/
printk_deferred_enter();
show_pwq(pwq);
printk_deferred_exit();
}
raw_spin_unlock_irqrestore(&pwq->pool->lock, flags);
/*
* We could be printing a lot from atomic context, e.g.
@ -4849,7 +4857,12 @@ void show_workqueue_state(void)
raw_spin_lock_irqsave(&pool->lock, flags);
if (pool->nr_workers == pool->nr_idle)
goto next_pool;
/*
* Defer printing to avoid deadlocks in console drivers that
* queue work while holding locks also taken in their write
* paths.
*/
printk_deferred_enter();
pr_info("pool %d:", pool->id);
pr_cont_pool_info(pool);
pr_cont(" hung=%us workers=%d",
@ -4864,6 +4877,7 @@ void show_workqueue_state(void)
first = false;
}
pr_cont("\n");
printk_deferred_exit();
next_pool:
raw_spin_unlock_irqrestore(&pool->lock, flags);
/*